As home inspectors, it’s crucial that we can spot a wrong gauge wire with a circuit breaker. Even the nicest, most organized electrical panel, can have this dangerous situation. More experienced home inspectors can identify the gauge of a wire just by looking at it, but not all of us have developed that talent yet.  That why I sell the Wire Gauge Sample Pack.  It’s nice to be able to just hold up a sample wire near the suspicious conductor in the panel.  I’ve also put a chart down below.  It the relationship of copper wire gauge vs. circuit breaker amperage.


Here are some potential dangers of using the wrong gauge wire:

Overheating: If the wire is too thin, it may not be able to handle the current flowing through it, which can cause the wire to overheat. This can melt the insulation and potentially start a fire.


Tripping circuit breaker: If the wire is too thick, it may not be able to trip the circuit breaker when it is overloaded, which can cause the breaker to fail and potentially lead to an electrical fire.


Voltage drop: If the wire is too long or too thin, it can cause voltage drop, which can result in equipment failure or reduced efficiency of the equipment.


It is important to use the appropriate gauge wire with a circuit breaker to ensure safety and proper functioning of the electrical system. The appropriate gauge wire depends on the amperage rating of the circuit breaker and the length of the wire run. It is always best to consult a qualified electrician for proper installation and maintenance of electrical systems.


Copper Wire Gauge AWGCircuit Breaker Amperage
1415 amp
1220 amps
1025, 30 amps
835, 40 amps
645, 50, 60 amps
470 amps
290, 100 amps
1110 amps
1/0125, 150 amps
2/0175 amps
3/0200 amps
4/0250 amps